Centralized inventory systems are frequently used in the medical community to track and dispense medical products such as medications, medical devices, etc. Some of these items are sophisticated and expensive instruments, and keeping close track of these items is desirable from a caregiver viewpoint as well as an ownership viewpoint. For a caregiver, it is important to be able to quickly and accurately locate a needed item. As an owner of the facility, it is important that very expensive items, such as electronic instruments, be protected from theft to the extent possible.
In such a centralized inventory system, medical products are often stored in a storage area, such as a wall cabinet or other secure location. The dispensation of the products from the storage area can be tracked by requiring authorized users to indicate in a tracking log which products, and what quantity thereof, they have removed from the storage area. Similarly, low-stock and out-of-stock warnings can be provided by an alert user who notes the dwindling supply of a product as he removes it. These systems, however, rely upon the compliance of the users to track the dispensation of products therefrom, and are therefore prone to inaccuracy.
Certain inventory systems are automated for the tracking of inventory. For example, some known inventory tracking systems use RFID tags by placing a unique RFID tag on each item stored in a secure cabinet and having an RFID antenna located in or near the cabinet to monitor the presence of the items in the cabinet by detecting the presence of each unique RFID tag associated with each item. The RFID antenna in such systems is often connected to a processor or computer for tracking inventory, wherein the computer is locally provided in or near the cabinet or is connected remotely via a connection or network. Such RFID-based inventory systems conduct an inventory monitoring process by periodically scanning a storage area to identify all products currently stored in the storage area and creating a current inventory list. Then, such systems compare the current inventory list with a past inventory list to determine if any products have been removed. The problem with such systems is that this periodic “scan-and-discover” process requires significant time and processing resources until the scan is completed before the new current inventory list can be completed. This is because the “scan” is a general broadcast query which is not addressed to any particular wireless tag. All present wireless tags then respond to the scan broadcast signal with a generic response which is an invitation for further communication. Then, for each responding wireless tag, the system must send at least one secondary query directed specifically to the responding wireless tag to obtain its identification and to obtain information related to the corresponding tag and associated medical product. The wireless tag then responds with such information which is then processed and stored by the inventory monitoring system. It can be appreciated that this “scan-and-discover” process is cumbersome as it results in multiple communications between each wireless tag and the inventory monitoring system, including lengthy data transmissions from each wireless tag to the inventory monitoring system.